Sealless modular positive displacement dispenser

Abstract

Modular positive displacement apparatus (20) for dispensing precise quantities of a fluid product including a dispensing unit (22) and an actuator unit (26). A housing (30) of the dispensing unit (22) defines a reservoir (36) which contains the product under pressure. Within the housing is a ball-type closure mechanism (47, 49). A deformable (50) diaphragm isolates the reservoir from the mechanism (26) which actuates the dispensing unit (22) to prevent undesirable escape of the product. The diaphragm (50) may be of a number of shapes, depending upon the length of the stroke desired. The dispensing unit (22) is readily removable from the actuator unit (26) and can be readily replaced with another dispensing unit. Different nozzle (76) sizes can also be accommodated. The length of the stroke is adjustable in discrete increments.

What is claimed is: 
     
       1. Positive displacement pump apparatus for dispensing precise quantities of a fluid product comprising: a housing defining a fluid product reservoir and having an inlet for delivery of pressurized fluid product to said reservoir and including a closure surface defining an outlet for dispensing the fluid product from said reservoir;   a chamber intermediate said reservoir and said closure surface for receiving fluid product from said reservoir and for dispensing fluid product through the outlet in said closure surface closure means normally biased to a closed position in engagement with said closure surface;   actuator means including an operation mechanism and an actuator shaft member extending away from said operative mechanism a stem member coaxially with and mounted on said actuator shaft member;   a product piston mounted to an extremity of said stem member, distant from said operative mechanism, and movable between an inactive position within said reservoir withdrawn from said chamber and an active position sealingly, slidably received within said chamber to move said closure means, by means of the fluid product within said chamber, to an open position and thereby dispense the fluid product from said chamber; and   sealless sealing means fixed to said housing and to said stem member and extending therebetween for isolating said reservoir from said operative mechanism, said sealing means being deformable to permit movement of said product piston between said inactive and active positions.   
     
     
       2. Positive displacement pump apparatus as set forth in claim 1 wherein said closure means includes:   a check ball; and   a spring biasing said check ball into sealing engagement with said closure surface.   
     
     
       3. Positive displacement pump apparatus as set forth in claim 1 wherein said housing has a longitudinal axis along which said chamber and said closure surface are centrally disposed, said stem member being movable along said longitudinal axis; and   wherein said seallness sealing means is a deformable diaphragm extending transversely of said actuating axis fixed at spaced regions, respectively, to said housing and to said stem member.   
     
     
       4. Positive displacement pump apparatus as set forth in claim 3 wherein said diaphragm is fixed to said stem member intermediate said operative mechanism and said product piston. 
     
     
       5. Positive displacement pump apparatus as set forth in claim 4 wherein said diaphragm has a central region fixed to said stem member and an outer peripheral region fixed to said housing.   
     
     
       6. Positive displacement pump apparatus as set forth in claim 5 wherein said outer peripheral region is integral with said housing.   
     
     
       7. Positive displacement pump apparatus as set forth in claim 5 wherein said diaphragm is a substantially planar disk. 
     
     
       8. Dispensing apparatus as set forth in claim 5 wherein said diaphragm is selected from the group consisting of: diaphragms having a generally concave shape;   diaphragms having a first fold member adjacent said central region and a second fold member adjacent said outer peripheral region, said first and second fold members intersecting at an annular apex which, when the central region and peripheral region are in a coplanar relationship, is displaced from said plane in directions parallel to said longitudinal axis, said annular apex being a living hinge such that said first fold member is movable toward a coplanar relationship with said second fold member upon movement of said stem member; and   diaphragms having a plurality of concentric fold members, each adjoining pair of fold members defining an annular apex being a living hinge, all of said fold members being movable toward a mutually coplanar relationship upon movement of said stem member from a position in which said peripheral region and said central region of said diaphragm are in a coplanar relationship.   
     
     
       9. Positive displacement pump apparatus as set forth in claim 3 wherein said chamber is shaped as a right cylinder whose inner sidewall is coaxial with said longitudinal axis of said housing; and   wherein a longitudinal axis of said stem member is generally substantially aligned with said longitudinal axis of said housing.   
     
     
       10. Positive displacement pump apparatus as set forth in claim 9 wherein said reservoir is generally shaped as a right cylinder whose diameter is greater than that of said chamber; and   wherein said housing has a cone-shaped surface intermediate said reservoir and said chamber for guiding said product piston into sliding sealing engagement with said inner sidewall of said chamber as said stem member moves between said inactive position and said active position.   
     
     
       11. Positive displacement pump apparatus as set forth in claim 10 wherein said stem member is flexible in directions transverse of said longitudinal axis of said stem member; and   wherein said product piston has a contoured outer surface slidably engageable with said cone-shaped surface through a range of relative angularly disposed positions;   said cone-shaped surface and said outer surface of said product piston being mutually effective to guide said piston into sliding sealing engagement with said inner sidewall of said chamber when the longitudinal axis of said stem member is misaligned relative to said longitudinal axis of said housing.   
     
     
       12. Positive displacement pump apparatus as set forth in claim 11 wherein said product piston is substantially spherical.   
     
     
       13. Dispensing apparatus as set forth in claim 1 wherein said operative mechanism includes a cylinder and a fluid operated drive piston axially movable in said cylinder, along an actuating axis, between first and second positions, said first position coinciding with said product piston being in the inactive position and said second position coinciding with said product piston being in an active position. 
     
     
       14. Dispensing apparatus as set forth in claim 1 including nozzle means mounted to said housing for receiving product from said chamber and for accurately directing the flow of the fluid product from said housing. 
     
     
       15. Dispensing apparatus as set forth in claim 14 wherein said nozzle means includes a hollow needle member and fastener means engageable with said housing for releasably joining said needle member thereto.   
     
     
       16. A positive displacement pump apparatus as set forth in claim 1 wherein said actuator shaft member is attached to said stem member in an end-to-end relationship, intermediate said operative mechanism and said sealless sealing means. 
     
     
       17. The modular system as set forth in claim 1 including an adjustment means for selectively adjusting operation of said actuator means enabling movement of said product piston between the inactive position and any one of a plurality of active positions. 
     
     
       18. Positive displacement pump apparatus as setforth in claim 1 wherein said stem member is integral with said actuator shaft member. 
     
     
       19. Positive displacement pump apparatus as setforth in claim 1 wherein said stem member and said actuator shaft are releasably attached in end to end relationship. 
     
     
       20. Positive displacement pump apparatus as setforth in claim 1 wherein said product piston is releasably attached to said stem member. 
     
     
       21. Apparatus for dispensing precise quantities of a fluid product comprising: dispensing means including a product piston and a chamber for receiving the fluid product to be dispensed;   actuator means comprising an operative mechanism for moving said product piston from an inactive position withdrawn from said chamber and an active position sealingly, slidably received within said chamber to effect dispensing of the fluid product by positive displacement, and an actuator body; and   adjustment means for selectively adjusting operation of said actuator means enabling it to effect movement of said product piston between the inactive position and any one of a plurality of active positions, said adjustment means comprising a threaded shank integral with said operative mechanism, a tubular stud internally threaded and threadedly engaged with said shank, said tubular stud also being externally threaded, a stroke adjuster nut threadedly received on said tubular stud and keyed to said actuator body to prevent relative rotation therebetween about an actuating axis of said actuator body, said adjuster nut being movable along said actuating axis coincidental with the rotation of the tubular stud about the actuating axis to a plurality of positions between and including a first position, relative to actuator body, wherein said operative mechanism is rendered inoperable and said product piston non-movable or wherein said operative mechanism is operable but said product piston is in an inactive position and a second position, distant from the first position, wherein said operative mechanism is operable and said product piston when in the active position has proceeded to its greatest possible depth into said chamber.   
     
     
       22. Apparatus for dispensing precise quantities of a fluid product as set forth in claim 21 wherein said dispensing means includes (i) a housing defining a reservoir for the fluid product and having an inlet for delivery of the fluid product to said reservoir and a closure surface defining an outlet for dispensing the fluid product from said reservoir and (ii) closure means normally biased to a closed postion in engagement with said closure surface; and   wherein said chamber is intermediate said reservoir and said closure surface, and said product piston, when in the inactive position withdrawn from the chamber, is within said reservoir.   
     
     
       23. An apparatus for dispensing precise quantities of a fluid product as set forth in claim 22 wherein said product piston is attached to a proximal, as regards said chamber, end of a stem member extending away from said chamber; and   wherein said actuator means includes an elongated actuator shaft member extending away from said operative mechanism, said actuator shaft member being attached to a distal end of said stem member in an end-to-end relationship.   
     
     
       24. An apparatus for dispensing precise quantities of a fluid product as set forth in claim 23 wherein said actuator body comprises a cylinder and said operative mechanism comprises an actuator piston means contained within said cylinder, said actuator piston means attached to said elongated actuator shaft member, and operative means for effecting reciprocation of the actuator piston means along an actuating axis. 
     
     
       25. An apparatus for dispensing precise quantities of a fluid product as set forth in claim 24 wherein said actuator piston means is fluid operable. 
     
     
       26. An apparatus for dispensing precise quantities of a fluid product as set forth in claim 24 further comprising resilient means for biasing said actuator piston such that said product piston is in an inactive position. 
     
     
       27. Dispensing apparatus as set forth in claim 23 including: sealless sealing means fixed to said housing and to said stem member and extending therebetween for isolating said reservoir from said operative mechanism, said sealing means being deformable to permit movement of said product piston means between said inactive and active positions.   
     
     
       28. Dispensing apparatus as set forth in claim 21 wherein said adjustment means includes means for setting in discrete incremental steps each of said plurality of second positions. 
     
     
       29. Dispensing apparatus as set forth in claim 21 including manual means for rotating said stud to thereby move said adjuster nut between said first and second positions. 
     
     
       30. Dispensing apparatus as set forth in claim 21, including manual means for rotating said stud in discrete incremented steps to thereby move said adjuster nut in similar discrete incremental steps between said first and second positions. 
     
     
       31. Dispensing apparatus as set forth in claim 32 wherein said manual means includes:   a crown member fixed to said stud, said crown member including an integral annular skirt overlying said actuator body and having a plurality of longitudinally extending grooves generally parallel to said actuating axis;   a spring biased detent ball mounted in said adjuster nut and successively engageable with each of said grooves;   whereby rotation of said crown member about said actuating axis results in a predetermined movement of said adjuster nut along said actuating axis.   
     
     
       32. Dispensing apparatus as set forth in claim 31 wherein said crown member is threadedly engaged with said stud; and including:   set screw means for fixedly joining said crown member to said stud.